In ordinary daily life, all kinds of lighting apparatus can be seen everywhere, such as fluorescent lamps, street lamps, table lamps, artistic lamps and so on. In the above-described lighting apparatus, the tungsten bulb is traditionally used as a light-emitting light source. In recent years, due to the ever-changing technology, light-emitting diode (LED) has been used as a light source. Moreover, in addition to lighting apparatus, for the general traffic signs, billboards, headlights etc., light-emitting diode (LED) has also been used as a light source. The light-emitting diode (LED) as a light source has the advantages of energy-saving and greater brightness. Therefore, it has been gradually common.
With the popularity of LED lamps, more and more occasions start using LED lamps, but as we all know, LED lamps are powered by a dedicated LED power supply. At the same time, with the improvement of living standard, people need the LED lamps with variable brightness output, therefore, the LED power supply with variable output power is needed. In the prior art, there are many LED power supplies that can change the output brightness of the LED lamps and have a variable output power. However, these LED power supplies in some cases do not give users a very good experience of using light, for example, in display lighting or in the museum, users prefer to use a mobile phone or a camera to photograph the displayed items. However, the existing LED power supply with variable output power makes the light source form streaks in the photographs taken by the cell phone or the camera. The streaks make the picture distorted, and affect the user's light experience.